アスタチン(At)には、33種類の同位体が知られている。全て放射性同位体で、原子量は191から223の間である。23種類の準安定励起状態も存在する。最も寿命の長い同位体は210Atで、半減期は8.3時間である。最も寿命の短い同位体は213Atで、半減期は125ナノ秒である。
同位体核種 | Z(p) | N(n) | 同位体質量 (u) | 半減期 | 核スピン数 | 天然存在比 | 天然存在比 (範囲) |
励起エネルギー |
191At | 85 | 106 | | 1.7(+11-5) ms | (1/2+) | | |
191mAt | | 2.1(+4-3) ms | (7/2-) | | |
192At | 85 | 107 | 192.00314(28) | 11.5(0.6) ms | 3+# | | |
192mAt | 330(90)# keV | 88(6) ms | (9-,10-) | | |
193At | 85 | 108 | 192.99984(6) | 28(+5-4) ms | (1/2+) | | |
193m1At | 50 keV | 21(5) ms | (7/2-) | | |
193m2At | 39 keV | 27(+4-5) ms | (13/2+) | | |
194At | 85 | 109 | 193.99873(20) | ~40 ms | 3+# | | |
194mAt | 480(190) keV | ~250 ms | 10-# | | |
195At | 85 | 110 | 194.996268(10) | 328(20) ms | (1/2+) | | |
195mAt | 34(7) keV | 147(5) ms | 9/2-# | | |
196At | 85 | 111 | 195.99579(6) | 253(9) ms | 3+# | | |
196m1At | -30(80) keV | 20# ms | 10-# | | |
196m2At | 157.9(1) keV | 11 µs | 5+# | | |
197At | 85 | 112 | 196.99319(5) | 0.390(16) s | (9/2-) | | |
197mAt | 52(10) keV | 2.0(2) s | (1/2+) | | |
198At | 85 | 113 | 197.99284(5) | 4.2(3) s | (3+) | | |
198mAt | 330(90)# keV | 1.0(2) s | (10-) | | |
199At | 85 | 114 | 198.99053(5) | 6.92(13) s | (9/2-) | | |
200At | 85 | 115 | 199.990351(26) | 43.2(9) s | (3+) | | |
200m1At | 112.7(30) keV | 47(1) s | (7+) | | |
200m2At | 344(3) keV | 3.5(2) s | (10-) | | |
201At | 85 | 116 | 200.988417(9) | 85(3) s | (9/2-) | | |
202At | 85 | 117 | 201.98863(3) | 184(1) s | (2,3)+ | | |
202m1At | 190(40) keV | 182(2) s | (7+) | | |
202m2At | 580(40) keV | 460(50) ms | (10-) | | |
203At | 85 | 118 | 202.986942(13) | 7.37(13) min | 9/2- | | |
204At | 85 | 119 | 203.987251(26) | 9.2(2) min | 7+ | | |
204mAt | 587.30(20) keV | 108(10) ms | (10-) | | |
205At | 85 | 120 | 204.986074(16) | 26.2(5) min | 9/2- | | |
205mAt | 2339.65(23) keV | 7.76(14) µs | 29/2+ | | |
206At | 85 | 121 | 205.986667(22) | 30.6(13) min | (5)+ | | |
206mAt | 807(3) keV | 410(80) ns | (10)- | | |
207At | 85 | 122 | 206.985784(23) | 1.80(4) h | 9/2- | | |
208At | 85 | 123 | 207.986590(28) | 1.63(3) h | 6+ | | |
209At | 85 | 124 | 208.986173(8) | 5.41(5) h | 9/2- | | |
210At | 85 | 125 | 209.987148(8) | 8.1(4) h | (5)+ | | |
210m1At | 2549.6(2) keV | 482(6) µs | (15)- | | |
210m2At | 4027.7(2) keV | 5.66(7) µs | (19)+ | | |
211At | 85 | 126 | 210.9874963(30) | 7.214(7) h | 9/2- | | |
212At | 85 | 127 | 211.990745(8) | 0.314(2) s | (1-) | | |
212m1At | 223(7) keV | 0.119(3) s | (9-) | | |
212m2At | 4771.6(11) keV | 152(5) µs | (25-) | | |
213At | 85 | 128 | 212.992937(5) | 125(6) ns | 9/2- | | |
214At | 85 | 129 | 213.996372(5) | 558(10) ns | 1- | | |
214m1At | 59(9) keV | 265(30) ns | | | |
214m2At | 231(6) keV | 760(15) ns | 9- | | |
215At | 85 | 130 | 214.998653(7) | 0.10(2) ms | 9/2- | | |
216At | 85 | 131 | 216.002423(4) | 0.30(3) ms | 1- | | |
216mAt | 413(5) keV | 100# µs | (9-) | | |
217At | 85 | 132 | 217.004719(5) | 32.3(4) ms | 9/2- | | |
218At | 85 | 133 | 218.008694(12) | 1.5(3) s | 1-# | | |
219At | 85 | 134 | 219.011162(4) | 56(3) s | 5/2-# | | |
220At | 85 | 135 | 220.01541(6) | 3.71(4) min | 3(-#) | | |
221At | 85 | 136 | 221.01805(21)# | 2.3(2) min | 3/2-# | | |
222At | 85 | 137 | 222.02233(32)# | 54(10) s | | | |
223At | 85 | 138 | 223.02519(43)# | 50(7) s | 3/2-# | | |
参考文献[編集]
- Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
- Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
- Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
- Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
- David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.